Twist Multiplier Research Articles

Prediction and Control of Surface Texture of Single Direction Crepe

A number of plain weave silk-like polyester fabrics with different surface texture were collected, data of fabric structural parameters were analyzed, and surface texture characteristics were tested. According to the relationship between structural parameters data and surface texture characteristic value, firmness and weft twist factor were found to be the main factors that affect the surface texture of single direction crepe. Finally, let tightness and weft twist multiplier be contributing factors, surface texture characteristics of single direction crepes were obtained by data analysis and regression equations.

RELATIVE IMPORTANCE OF FIBER PROPERTIES AFFECTING YARN HAIRINESS IN SOME EGYPTIAN COTTON VARIETIES

undesirable, depending on the application for which the yarn is being used. Hairy yarns provide good heat retention and a softer hand (feel) for finished fabrics, and except for a few special cases, when it is an excessive degree of hairiness, yarn hairiness is an undesirable property in yarn and can cause serious problems in both yarn production and in subsequent textile processes. This search was carried out to investigate the most important fiber properties i.e. short fiber content (SFC w %), maturity ratio, micronaire value, uniformity index (UI %), fiber length (UHM) and fiber strength (g/tex) which correlated with yarn hairiness and also their relative contributions in yarn hairiness under study by using four Egyptian cotton varieties during season 2008, namely; Giza88, Giza86, Giza80 and Giza90 spun into carded ring and compact yarns at twist multiplier 3.6 and two into counts according to the following: ring yarns were processed to carded yarns Ne 50 and 60. Compact yarns were also processed to carded yarns at the same counts. The most important results were: 1- Yarns manufactured by the carded ring spinning frame are characterized by higher hairiness mean values in all studied varieties in comparison with those of carded compact frame. 2- The correlation coefficients have positive signs and are very high between hairiness in yarns and short fiber content (SFC w %), on the contrary the correlation coefficients have negative signs being high or very high between maturity ratio, micronaire value, uniformity index (UI %), fiber length (UHM) and fiber strength (g/tex) and yarn hairiness in all varieties. 3- Stepwise regression procedure was employed to determine the most effective independent variables which make the maximum contributions to the coefficient of determination (R²). The rate of improvement in yarn hairiness index due to decrease short fiber content (the larger the share of fibers in the shorter length the higher is the hairiness index), increase fiber strength (more mature fiber) and increasing fiber length (the larger the share of the fibers in longer length the lower is the hairiness index

Packing of micro-porous yarns. Part II: optimization of fabric characteristics

This paper is concerned with the study of the characteristics of plain woven fabric produced with micro-porous cotton yarns in weft. The micro-porous yarns with varying packing densities and level of pore volumes are produced by changing proportion of PVA fibre content in the blend, yarn twist multiplier (TM) and spindle speed at ring frame. The micro-pores within the structure of the yarn have been created by dissolving the PVA fibres using washing treatment in hot water. A three-variable factorial design technique proposed by Box and Behnken has been used to study the interaction effects of these variables on the characteristics of fabrics. The influence of these three variables on the mechanical, handle and comfort properties of fabrics are studied, the response-surface equations for all the properties have been derived and the design variables are optimized for various fabric properties. Improvements in bending resistance, abrasion resistance and compressional characteristics have been observed with incorporation of micro-pores within the yarn structure. These fabrics with micro-pores have improved thermal resistance and moisture vapour transmission compared to that of 100% cotton fabric.

DEPENDENCE OF YARN AND FABRIC STRENGTH ON THE STRUCTURAL PARAMETERS

Abstract Strength of the fabric is an important property that decides and influences all other performance properties of the fabric. But though we all understand the importance of the strength of the fabric in daily wear, a systematic approach is required to correlate various strength properties with that of the yarn and fabric construction parameters. We are all aware of the effect of the individual factors like twist, count and cover factor on the strength behaviour of the fabric. However it is necessary to study the effect of all these parameters in combination with each other to ultimately influence the strength of the fabric. Such a study is also useful for designing of the fabric, depending upon the end use and the customer requirement as it is gaining importance in the recent fierce competitive scenario. In this study we have evaluated the strength properties of the fabric with respect to tensile, tear and bursting strength and correlated the results with respect to the yarn count, Twist Multiplier and picks per inch of the fabric using regression equations.

COMPARISON BETWEEN RING AND COMPACT SPUN FROM LONG STAPLE EGYPTIAN COTTON VARIETIES

This study has been done to compare ring and compact yarns spun from Egyptian long staple varieties .six long staple cotton varieties were used as Giza 80, Giza 83, Giza 90, Giza 85, Giza 86 and Giza 89 ,chosen to produce 40's count yarn spun at three different twist multiplier;3.2, 3.6 and 4.0. The obtain data cleared that:- The compact spun yarns at low twist level had better yarn property values - thin and thick places, nep values, yarn hairiness, yarn evenness, yarn strength and elongation at break (%) - than the conventional ring spun yarns for long staple Egyptian cotton varieties in the same twist level .i.e. yarn strength of the compact yarn was 11%higher than the conventional ring spun yarn. In addition, Compact yarns reached maximum strength at a lower twist multiplier than conventional ring yarns. Increasing twist caused a reduction in the number of thin and thick places and yarn hairiness in both compact and ring yarns While Elongation at break and Strength values increased with higher twist for both spinning systems. The data revealed that, Giza 86 variety was superior in fiber strength (cN/tex) and Giza 90 variety was superior in yarn evenness and hairiness values than other varieties.

Comparison of artificial neural network and linear regression models for prediction of ring spun yarn properties. I. Prediction of yarn tensile properties

In this study artificial neural network (ANN) models have been designed to predict the ring cotton yarn properties from the fiber properties measured on HVI (high volume instrument) system and the performance of ANN models have been compared with our previous statistical models based on regression analysis. Yarn count, twist and roving properties were selected as input variables as they give significant influence on yarn properties. In experimental part, a total of 180 cotton ring spun yarns were produced using 15 different blends. The four yarn counts and three twist multipliers were chosen within the range of Ne 20–35 and αe 3.8–4.6 respectively. After measuring yarn tenacity and breaking elongation, evaluations of data were performed by using ANN. Afterwards, sensitivity analysis results and coefficient of multiple determination (R2) values of ANN and regression models were compared. Our results show that ANN is more powerful tool than the regression models.

The Comparison of Cotton Knitted Fabric Properties Made of Compact and Conventional Ring Yarns Before and After the Printing Process

Compact spinning is a new version of ring spinning and the most distinct features of these yarns are their high strength and elongation values and low hairiness. In this study, we attempted to find the differences between compact and conventional ring knitted fabrics. One hundred % cotton yarns, produced from the same cotton blend, were spun according to compact and conventional ring spinning principles in two different yarns counts and twist multipliers. Three different knitting structures, interlock, rib and single jersey, were produced from these yarns. The physical properties of these fabrics were investigated and compared with each other before and after the printing processes. When the results were studied, it was seen that hairiness of compact yarns was less and their strength and elongation percentages were higher. They showed less tendency to pilling and had higher bursting strength. No statistical differences were observed with regard to weight, abrasion resistance, color efficiency and rubbing fastness.

Packing of micro-porous yarns: Part I. Optimization of yarn characteristics

The present paper deals with the factors affecting the packing of a micro-porous yarn, namely proportion of PVA fibre content, yarn twist multiplier (TM) and spindle speed at ring frame, and with their combined effect on various properties of the yarn. The micro-pores within the structure of the yarn have been created by dissolving the PVA fibres using washing treatment in hot water. A three-variable factorial design technique proposed by Box and Behnken is used to investigate the combined interaction effect of the above variables on the properties of the yarn. The present experiment variables, namely proportion of PVA fibre, yarn twist multiplier (TM) and spindle speed, were found to have significant impact on various properties of yarns before and after wash. For yarns before wash, the specific volume reduces with the increase in the PVA content, yarn twist and spindle speed. In the case of yarns after wash, there is reduction in the yarn specific volume with the increase in TM and spindle speed, but with the increase in the PVA percentage the yarn specific volume increases. The tenacity of yarns before wash increases with the increase in the PVA content, but for yarns after wash, the proportion of PVA content has comparatively less influence. The compressibility of yarns before wash reduces with the increase in the PVA content, but a reverse trend is observed in the case of yarns after wash. The design variables were optimized for all the yarn properties by using the response surface equations.

Property Analysis of Denim Fabrics Made on Air-jet Weaving Machine Part II

In the second part of the study, 3/1 left-hand twill denim fabrics were woven with different filling yarns. The yarn characteristics are correlated to filling tension. Experimental results have shown that yarn count, twist multiplier, hairiness, friction coefficient and other yarn properties have effects on filling tension and filling tension affects the fabric properties. Fabric properties — fabric weight, thickness, air permeability, dimensional stability, abrasion resistance, drapeability, stiffness, wrinkle recovery, tear strength and tensile strength — were tested. It was found that tension had significant effects on some fabric properties. The relationships between fabric properties and filling tension were established.

Continuous Spun-Like Textured Yarn Processed with Various Plied Filaments and Different Stages of Emery Wheels

A new rotor twister is used to fabricate spun-like filament yarns. The raw material, draw-textured yarn (DTY), becomes as the core yarn and the wrapping yarn. During twisting, the core yarn passes through a pair of emery wheels to make the surface hairy. In this experiment, the rotor speed, twist multiplier, number of emery wheels, and denier of the DTY are varied. The effects of these parameters on tenacity, elongation, and hairiness numbers are examined and discussed. Reducing the number of emery wheels increases hairiness but reduces tenacity and elongation. The twist multiplier influences both tenacity and elongation. Increasing the twist multiplier reduces the hairiness numbers but increases yarn strength. In addition, increasing the speed of the emery wheels under fixed processing conditions increases hairiness but also reduces the tenacity and elongation of the spun-like filament yarns.

Fiber Dynamical Analysis of Twist Draft Spinning

This paper presents an analysis of the fiber dynamics in the twist draft spinning, and an application of the derived theory from the analysis to TCTDS (Tension Control type Twist Draft Spinning), a kind of the twist draft spinning that is being developed by the authors.Through the analysis, we specially have regard for linear density and twist rate of the twist draft spinning yarn those are deeply concerned with the quality and structure of the yarn. And we found that the twist multiplier of the twist draft spinning yarn spun in steady state of the spinning process is formulated by a function of properties of raw materials, e.g., fiber length, fiber diameter, and the coefficient of inter-fiber friction.The theoretical result shows good agreement with the practical data of yarn properties given by the related experiments, and it proves to be a valuable tool in designing of yarns spun with TCTDS.

Structure and Properties of Cotton Sirospun® Yarn

Cotton Sirospun® yarn has a circular cross-sectional shape, with the two strands segregated and consolidated into an adjacent array. When it is untwisted, the strand twists in an alternate direction. When compared to single yam with the same linear density and twist multiplier, cotton Sirospun yam is superior in tenacity, evenness, hairiness, and abrasion resistance. Although cotton Sirospun yam is less hairy and more extensible than two-plied yarn, it is inferior to two-plied yam in evenness and imperfections.

Effect of spinning conditions on physical properties of a composite yarn

This study investigated the effects of spinning conditions such as traveller, twist multiplier, front top roller pressure and hardness on the physical properties of 19.7 tex Polyester/Rayon (P/R) composite yarns. Results showed that a traveller of #1/0, twist multiplier of 2.8, front top roller pressure of 18 kgf and hardness of 70° are the optimum spinning conditions. This combination results in the best mixing of spreaded polyester filaments and drafting rayon fibers in the nip of the front rollers, arranging them in the best dispersion to form a P/R composite yarn with better quality and good blend uniformity. The results also showed that the 19.7‐tex composite yarn spun in this study is superior to the world 5 % for standards of uniformity and hairiness. This indicates that the quality of P/R composite yarn has been remarkably improved.

Cross-Sectional Structure of Composite Yarns

This work investigates the effect of spinning conditions such as traveller, twist multiplier, and front top roller pressure and hardness on the cross-sectional structure of 19.7 tex T/R composite yarns. A traveller of #1 /0, a TM of 2.8, and a front top roller pressure of 18 kg and hardness of 70° are the optimum spinning conditions. This combination results in the best mixing of spread polyester filaments and drafting rayon fibers in the nip of the front rollers, arranged in the best dispersion to form a T/R composite yarn with better quality and good blend uniformity. The results reveal that the 61.5% asymmetrically sided type is the predominant cross-sectional structure of T/R composite yams. However, the fraction of the uniform distribution type increases from 10.0 to 24.5%. indicating that the blend uniformity of T/R composite yams improves remarkably.

Drafting Force of Fine Denier Polyester Fibers

In this paper, we use fine denier polyester fibers (0.8 denier) as the test material to measure drafting force in the break draft zone. The fundamental relationships between drafting conditions (such as drafting ratio, roller gauge, twist multiplier, and fiber mass) and drafting force follow the same trend as for cotton fibers. However, the drafting force curves reveal some differences between them. The character of the former reveals that it has a high drafting force value and a broader peak range. The force variation in the lower drafting ratio before the peak is low and steady, a very important parameter that is better correlated to the properties of spun yarn than the mean drafting force. In actual spinning, better quality yam is obtained with a suitably lower draft.

Effect of Strand Spacing and Twist Multiplier on Cotton Sirospun Yarn

For combed cotton yarns, the wider the strand spacing is in Sirospun, the better the yarn properties are in terms of tenacity, Uster hairiness, abrasion resistance, and trapped strand twist.

Efeito da torção na regularidade e na quantidade de neps em fios de algodão de títulos Ne20, Ne30 e Ne40

Estudaram-se a regularidade e a quantidade de "neps" em fios de algodão de títulos Ne20, Ne30 e Ne40 para diferentes coeficientes de torção, representados pelas constantes 3,4, 3,6, 3,8, 4,0, 4,2, 4,5 e 4,7. Utilizaram-se, para tanto, três variedades paulistas de algodoeiro: IAC 16, IAC 13-1 e IAC 17. Obtiveram-se a regularidade dos fios e a quantidade de "neps" por meio dos resultados fornecidos, respectivamente, pelo integrador e pelo contador de imperfeições, ambos da linha Uster Evenness Tester. Com base nos resultados, concluiu-se que, ao aumento do número de torções do fio, correspondeu o crescimento do número de "neps", o qual se intensificou, sucessivamente, nos títulos Ne20, Ne30 e Ne40, e, notadamente, nas variedades com tendência acentuada para essa anormalidade. Não se verificou efeito da torção na regularidade do fio. Títulos mais altos resultaram em aumentos na irregularidade e na quantidade de "neps", sobretudo em relação à IAC 13-1, mais sujeita a esses defeitos.

Illustration of stress/strain behavior and yarn fragmentation in a pseudo-hybrid composite system

To study the stress/strain behavior and the fragmentation of fibers in a hybrid composite in tensile loading, a model strand was constructed with cotton yarns as the low-elongation component and polyester yarns as the high-elongation component. The effect of interfacial shear strength on the performance of a hybrid composite was simulated by varying the twist multiplier of the strands. It was observed that a strand with a lower twist level was more likely to show a typical hybrid stress/strain behavior and a multi crack fragmentation pattern. The same was found for strands with the highest twist levels but with cotton contents between 22 and 33%.

A Study of The Diameter and Contraction of King Spun-Yarns.(Dept.T)

This paper presents some predicting formulas of yarn diameter and contraction of ring spun yarns. The study concerned the influence of twist multiplier, yarn count and bulk density. Experiments carried out on different cotton yarns to justify the results of the theoretical analysis. The results obtained with these empirical formulas agree satisfactorily with the actual data.

Influence of Cotton Waste fibre Properties, Twist Multiplier and Yarn Linear Density on Open-End Yarn Quality.(Dept.T)

Influence of Cotton Waste fibre Properties, Twist Multiplier and Yarn Linear Density on Open-End Yarn Quality.(Dept.T)